Amid Naomi Osaka's slump, concerns raised over her coaching relationship with Patrick Mouratoglou by Rennae Stubbs

Naomi Osaka’s 2025 season so far hasn’t panned out as she’d have hoped. Amid her slump, Serena Williams’ ex-coach Rennae Stubbs has raised concerns over her coaching relationship with Patrick Mouratoglou.

Osaka has posted nine tour-level wins this season, alongside five losses. The four-time Grand Slam champion featured in her first final in almost three years at the ASB Classic in January but retired injured mid-match. Naomi Osaka’s results since have been rather forgettable, with her best performance being the fourth round of the Miami Open.

After an intense training block with her coach Patrick Mouratoglou, the 27-year-old started her clay campaign at the ongoing Madrid Open but crashed out in the opener 6-4, 2-6, 6-4 against Italy’s Lucia Bronzetti.

On the recent episode of The Rennae Stubbs Tennis Podcast, Stubbs addressed Osaka’s partnership with Mouratoglou, opining that the pair may split up if she fails to produce favorable results soon.

"I don’t know, honestly, how long he’ll put up with it as well. He likes success, right? And so, it’s another interesting juxtaposition," she said.

"Yes, Naomi Osaka is a massive game and name in the sport of tennis, and clearly in the sport world – a lot of people have heard of Naomi Osaka. So, you just wonder how long he’s gonna sort of deal with that as well, and how long she’ll deal with it," Stubbs added.

The Japanese hired Patrick Mouratoglou after the 2024 US Open, having announced her separation from Wim Fissette, who now coaches Iga Swiatek. Meanwhile, the French coach picked up the gig after ending his on-again, off-again partnership with Holger Rune. Stubbs had her reservations about Osaka’s new collaboration at the time.

Before Rune, Mouratoglou coached Simona Halep and was widely known for his work with Serena Williams.

---

"Naomi Osaka never has to work another day in her life" – Rennae Stubbs

Naomi Osaka pictured at the 2025 Madrid Open - Image Source: Getty

Before starting her 2025 campaign, Naomi Osaka laid bare her feelings about lacking results despite putting in the hard yards. She also conveyed that she may not carry on if she fails to rediscover her top form.

Echoing a similar sentiment, Rennae Stubbs said on her podcast:

"I mean, she has all the money in the world; she never has to work another day in her life. How much does someone like her want to put herself through this consistently, on a weekly bases, where she’s not having results."

Despite the lingering uncertainty about her results, Osaka has ramped up her claycourt preparations ahead of the French Open. After her Madrid Open exit, the four-time Grand Slam champion entered the WTA 125K event in Saint-Malo, where she has reached the Round of 16 clash against French local Diane Parry after her 6-2, 6-1 win against Petra Marcinko.

"She’s playing a small tournament this week, which is interesting. I don’t know how much (Patrick Mouratoglou) had an influence on her to do that," Stubbs said. "I think it’s a smart thing; she’s playing against players that are nowhere near as good as her. So hopefully she can get a little bit of confidence."

The former player also noted that Osaka doesn’t have the best relationship with clay, but she was the only player who challenged Iga Swiatek at the 2024 French Open.

"Clay has never been her thing. So maybe she’s hoping to get some confidence going into the hardcourt, but still grasscourt is not really her thing," she pondered.

"We know she can play well on clay because she pushed Iga, arguably the greatest player we’ve seen on clay in the last five years on the women’s tour," Stubbs recalled.